An American college student who has been in North Korean custody for a year and a half arrived in Cincinnati on Tuesday night on a medical evacuation flight.

Otto Warmbier, 22, is in a coma, his father, Fred Warmbier, told NPR News on Tuesday. An ambulance took Otto Warmbier from the airport to the University of Cincinnati Medical Center.

Warmbier, a University of Virginia undergraduate, was visiting the North Korean capital, Pyongyang, as part of a student tour group. He was arrested in January 2016 and accused of trying to steal a propaganda poster from an employee area of his hotel.

After a brief trial broadcast by North Korean state television, Warmbier was sentenced to 15 years in prison and hard labor. In tears, he apologized for his actions.

State Department officials said Warmbier's release followed secret talks between U.S. and North Korean diplomats. Joseph Yun, the U.S. special envoy on North Korea, met with North Korean officials in Oslo, Norway, in May and reached an agreement for Swedish diplomats to visit Warmbier. Sweden represents U.S. diplomatic interests in North Korea.

Last week, North Korean officials told Yun about Warmbier's medical condition. Yun and two physicians flew to Pyongyang and visited Warmbier on Monday. Yun demanded his release and North Korea complied on Tuesday, according to the State Department.

Secretary of State Rex Tillerson announced Tuesday that Warmbier had been freed. The State Department said President Trump had been consulted. White House deputy press secretary Sarah Sanders told reporters aboard Air Force One on Tuesday night that "bringing Otto home was a big priority for the president."

Copyright 2017 NPR. To see more, visit